Compressor.



y E. M. MAGKIEW COMPRESSOR.

LPPLIOATIOH FILED IAB. 30, 1906.

Patented Ap r. "7, 1914.

3 SHEETS-11311??? 1.

E. M. MAOKIE.

COMPRESSOR. APPLIGIATION FILED MAR. so, 1906.

Patented Apr. 7, 1914 3 SHEETS-SHEET 2.

will I' MMM @MQ/ Y 1 WJ/W UNITED sTArnsrATENT OFFICE.

EDWIN M. MACKIE, OF NORTH TARRYTOWN, NEW YORK, ASSIGNOR T0 CHICAGO PNEUMATIC TOOL COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

COMPRESSOR.

Patented Apr. '7, 1914.

Application filed March 30, 1906. Serial No. 308,889.

To all whom it may concern Be it known that I, EDWIN M. h/lACKlE, a citizen of the United States, residing at North Tarrytown, Westchester county, New York, have invented certain new and useful Improvements in Compressors, of which the following is a specification.

My invention relates to air compressors and the object thereof is to pro-ride a means or system controlling the same whereby the motor or engine which drives the compressor shall be relieved of the load of such compressor until the latter has attaincda certain predetermined rate of speed, such conditions continuing until the speed of the compressor is reduced to a point below the predetermined degree, whereupon the motor is automatically unloaded, that is, relieved from the load of compression by the compressor. Thus the motor is caused to carry the load of the compressor only when a cer-, tain speed is reached or exceeded, while such motor is relieved of that load when its speed is less than said predetermined degree. In the present instance, said results are accomplished in automatic manner by valve mechanism adapted to prevent or interfere with compressing action, with the result that the compressor is caused to work without compression and to thereby impart no load to the motor when such motor is working at aspeed less than the predetermined speed and to work in its normal way when the motor reaches or exceeds said predetermined speed. By this means the motor is relieved of unnecessary strains when starting and moreover the said mechanism, including the motor and compressor, are enabled to begin effective work sooner than through systems or sets of apparatus unprovided with my unloading means.

In the drawings, Figure 1 is a view, more or less diagrammatic, illustrating the governorand air pressure controlling device or air governor in elevation and illustrating. a compressor system comprising a high pressure air cylinder and low pressure air cylinder, with the suction valve of one of the compressors as well as the fluid pressure actuated mechanism governing the suction actuated mechanism for controlling the same; and Fig. 5 an elevation partly in section of a modifled form of construction.

Reterrlng to the presentembodimcnt of my invention, I have chosen to illustrate a system having two double acting compression cylinders, in the present instance a low pressure air cylinder marked Ll. air cylinder and a high pressure air cylinder marked HI. air cylinder, although as will be understood. my invention is applicable to a system in which a single compression cylinder is employed. l'twill thereforebe understood that the same control may be had of a plurality of air compressors or compression cylinders and associated parts as of a single air cmnpressorhaving a single compression cylinder and associated parts.

For convenience, I will now proceed to describe my invention as embodied in the systom illustrated in the drawings. I

Only those parts of the compressors which are concerned with an understanding of my invention have been illustrated in detail, only one side of the two compressors 1, 1, be ing shown herein. The valve mechanism. particularly the suction or inlet-valve of the compressors may be of any suitable con-' struction, the Corliss type being herein adopted but only one end thereofloeing illustrated as at 1.

My means for unloading the motor and automatically controlling the compressing functions of the compressors are, in the present instance, located adjacent the suction valves and are so arranged that the compressors will work without compression until such time as the motor reaches or exceeds apredetermined speed, whereupon the interference with the usual functions of the compressors will be removed and the normal operation thereof will be permitted to take place. My, said means comprises, as shown, a so-called unloader valve under the control of fluid pressure actuated mechanism which is itself under the control. of a governor responsive to variations in the rate of compressor speed. The unloader valves for the compressors are similar, so that a description of one of them will apply to all, which are four in number in the present instance.

As herein shown, the nnloader valve 2 is of thepuppet type and contained within a valve bonnet 3 secured tothe compressor casing in suitable manner. This bonnet is provided in its interior with a gulde sleeve 4 for guiding the stem 5 of the valvewhich is normally held seated by a suitable spring such as the spring 6 bearing on the inner side of the valve. In the present instance,

the inner end of the springis contained 7 within a spring seat or thrust collar 6*,

which bears against one end of the Corliss suction valve 1. In the outer open end of the bonnet is secured by screwing or otherwise a cylinder-7 open at its inner end but closed at its outer end' except as to a port or passage8 arranged to communicate with the main reservoir or receiver as determined by the governor mechanism herelnafter described. Withm this cylinder travels a pis- .ton 9 having on its inner side a boss or stem 10 which is arranged axially of the unloader valve stem 5 and in the path of themovement of the latter, with the result that when the piston 9 is moved inwardly by pressure exerted on its outer pressure area said valve ismoved inwardly and off its seat against the tension of the spring 6, so that the compressor will now work without compression. The chambers 2 bf the unloader valves at the ends of each cylinder communicate with each other through the connecting pipe 2 and each chamber 2"" compression cylinders are connected by a pipe 11, while those of the low pressure compression cylinder are connected by a similar pipe 12. The two pipes 11 and 12 are connected to a common cross pipe or connection 13, which, by means of another pipe 14:, communicates with the governor device which is itself connected by suitable connection or pipe such as pipe 15 with an ordinary main reservoir or receiver, not shown.

Referring next to the governor, the same, as to the main portions thereof, is of the usual and well-known constructionof centrifugal or ball governor, but the part or parts thereof Which are movable according I to the speed. of the compressor, instead of being employed to shut off the steam" or motivev power, are "employed to control valves which regulate the admission and exhaustof air pressure to and fromthe cylinders 7 through the system of piping hereinbefore described. The rotation of the balls 16 of the governor in the well-known manner is adapted to control thereciprocations of two rods or plungers 17 and 18, the plunger 17 being mounted in and carried by a reciprocating member or head 19, while the other plunger 18 is mounted in and carried by a movable member or head 20. So that the two plungers shall move in unison, I con nectthem through the medium of their supporting members by means of a yoke 21.

The plungers 17 and 18 are adjustable in rotated by a connection with the main shaft (not shown) of the compressor, the connection being in the present instance with a sprocket wheel 25, whose shaft 26 is op eratively connected with the balls. The centrifugal governor is provided with what I will for convenience term an air governor,

which directly controls the admission and exhaust of air pressure to and from said cylinder? of the unloader valves, such air governor having valves which are under the control of the plungers 17 and 18. In the present instance this air governor comprises a casing 27 having the two valve chambers 28 and 29, both having ball valves 30 and 31 respectively. The valve 30 is the inlet valve controlling the inlet or admission of the air pressure from the receiver to the cyl inders 7 and the valve 31 is the exhaust valve for releasing the air pressure thus admitted by the inlet valve to said cylinder 7. The inlet valve chamber 28 is arranged to communicate with the supply pipe 15 leading from the receiver through a port and passage 32 and to communicate with the system of piping through a port 33 through the lower end of the inlet valve chamber 28 and governed by the'ball valve 30. 'This port 33 communicates with a passage 34 leading upwardly through the valve casing and connecting with a cross passage 35 which communicates both with the system of piping through the pipe 14 and with the exhaust valve 31 is opened so as to release the compressed air from said cylinder 7, the admission valve 30 is closed. Both of the valves 30 and 31 have a tendency to close because of the provision of the springs 38 and S9. The ball valves 30 and 31 are controlled automatically by the centrifugal ball governor in the following manner by the plungers 17 and 18: The plunger 17 is arranged to reciprocate in a guide or bushing 4-0 in the frame of the centrifugal governor and the lower end of such plunger extends through the port and passage 36 and radially of the ball valve 31 in a position to contact such valve and force the same inwardly into its chamber and off its seat against the tension of the spring 39. The other plunger 18 extends through a suitable stntling box 411 and upwardly through the port 33, radially of the ball valve 30 and in position to contact such ball valve and thereby lift the same from its seat against the tension of its spring 38, which tends to hold such valve seated. \Vhen the apparatus is at rest. the unloader valves are thus unseated because at this time the air governor connects the air receiver with all of the cylinders 7, and this condition will continue so long as the air governor remains in that position and so long also as there is any air pressure in the receiver. Assuming that it is now desired to start up the compressor, it. will be observed that the engine or motor is not compelled to carry the load of the compressors as the same are at this time in a condition to work without compression, inasmuch as the air in each cylinder will be by-passed from one end to the other alternately through the ports 1 in each end of the suction valves, through chamber 2* and connecting pipes 2., and this condition continues until the speed of the main shaft of the compressor ,reaches a predetermined amount. The engine or motor thus runs freely without the load of the compressor until it has imparted to such main shaft of the compressor a certain predetermined number of revolutions per minute, at which time the centrifugal governor will be caused to operate the air governor in such manner as to cut off the communication of the air receiver and the cylinders 7 and to open the exhaust from said cylinders 7 to the atmosphere, whereupon the unloader valves will.

close and thereby permit the compressors to compress the air. The compression will thus be delayed until the motor has attained a predetermined speed and the compressors will be delayed in their effective or compressing operations until that speed is reached. The operation of loading and unloading the motor is thus automatic in all of its operations. The compressors continue to work with compression so long as said predetermined speed is maintained or exceeded, and

' until the speed is reduced below said predetermined degree, whereupon the centrifugal governor will cause exhaust valve 81 to close and the inlet valve 30 to open so as to admit the air pressure of said cylinders 7 and the unloader valves to be thereby opened and held open. The pipe 2 which is referred to as a by-pass thus forms a closed circuit between the opposite ends of its cylinder, that is there are no connections or communications with the atmosphere so that when the unloader valves are operated in the manner already explained, the air passes from one end of the cylinder to the other without compression and without giving any load whatever to the compressor, said by-pass being made of suflicie-nt carrying capacity that there shall not be any interference with the flow of the air alternately in opposite directions. Moreover the uirloader valves are placed adjacent the ends of the by-pass with the result that in the ordinary operation of the compressor there will be practically no clearance or dead spaces which would interfere with the etliciency of the compressor. By reason of this construction and arrangement, particularly because of the provision of a closed circuit as distinguished from one having connnunication with the atmosphere there is no possibility of any waste of energy as would result were the ends of the cylinder open to the atmosphere in which event energy especially in a fast-running compressor would be expended. According to my construction I am enabled to bypass the contents of the compression end of the cylinder to the intake end thereof alternately in uniformity with the reciprocations of the piston and without any possibility of waste of energy.

In the event that the motive power is an electric motor and assuming that the desired air yressure has been reached, a suitable air-electrical device may be provided to shut off the current, in which case the machine will begin to slow down. Vhen the motion is decreased a certain predetermined. amount the centrifugal or fly balls will have dropped somewhat so as to decrease the downward pressure exerted by them on the yoke 21, thereby permitting the spring 22 to act upwardly on the yoke and the plun;

gers 17 and 18 in the described operationof the air governor.

The tension of the spring against which the centrifugal balls 16 operate is adjustable by means of the adjusting screw 23, which may be screwed up or down to increase or decrease the tension of that spring as may be required. Moreover the plungers 17 and 18 may be adjusted to 'ary the prcdetermined speed at which the motor 4:1 engine takes up the compressor so far as compress ing action is concerned. Thus by ad ustmg the plungers 17 and 18 dtnvnwardly the said predetermined speed may be changed so as to require a greater speedbefore the compressors are caused to compress and the reverse is true'of an upward adjustment of said plungers. Furthermore the arrangement is such that these plungers may be attached independently so that, if desired, there may be a predetermined period of time between the closing of one of the ball valves and the opening of the other, as may be desired. I

Itis obvious that my compressor may be operated by any suitable motive power such as a steam engine, electric motor or the like and therefore it will'be understood that I use theterm motor throughout this specification in its general or generic sense, as relating to any prime mover. I It will also be .understood that the parts constituting my improvements are applicable to governors of well known construction other than the fly 'ceeded, the fly ball governor forces the lever ball governor herein shown.

My invention may be embodied in other forms of construction, particularly as to the so called air governor or valve mechanism for admitting .and releasing the pressure to and from the fluid pressuremechanism controlling the suction valve and as exhibiting this fact, I have in Fig. 5 illustrated a modified form of construction of such governing valve mechanism, in which I employ a valve casing 42 having a port 43 communicating with the atmosphere,'a port and passage 44 communicating through pipe 45 with a source of compressed air and a port and passage 46 communicating through pipe 47 with the fluid pressure actuated mechanism which governs the suction valves of the compressor system. In the present instance, instead of employing two separate and independent valves, I employ a single valve 48 which, as shown, is of the piston type and provided intermediate its length with a circumferen- -tial groove or waste portion 49, which is arranged to control said ports in the valve casing. 'As will be understood from an examination of Fig. 5, the valve is shown in position to connect ports 44 and 46, withthe result that compressed air is admitted to said fluid pressure actuated mechanism. When, however, the valve is depressed, in the mannerlhereinafter explained, against the tension of the'spring 50, which tends to keep the valve in its upward position, the

port 46 will be brought into communication with the exhaust port 43, with "the result that said fluid pressure actuated mechanism will be released. The tension of the spring 50 is adjustable by means of the screw plug 51,-against which the lower end of the spring abuts and which is arranged'to be screwed into the lower end of the cylinder or valve casing 42. The valve 48 is operatively connected with the same type of fly ball governor 52 as in the preferredform of construction hereinbefore described, but is operated in a somewhat different manner. As herein shown, the governor has a vertically movable rod or plunger 53 which is arranged to bear upon the upper edge of a lever 54 at a point intermediate the length of the latter. This lever is fulcrumed at one end at'55, such fulcrum being a ,fixed one, while the other end of the lever bears with its lower edge against the vertical fulcrum pin or plunger 56 which enters through the top of 'the valve cylinder or casing 42 and bears against the upper end of thevalve 48. As will be readily understood, the valve 48 is shown in its normal position, that is its posi-.

tion when the apparatus is at rest or when the compressor is working at low speed and has not reached its predetermined rate of I speed. When such rate of speed is reached and during the time that the same is ex- It will be understood from an examination of Figs. 1 and 4 that the unloader valve may itself perform the functions of a puppet type of suction valve, in which event the Corliss type of valve would be dispensed with and the valve 2 herein will thereupon perform the double. functions of a suction valve and an unloader valve. It will there- 'fore' be understood that my broader claims are not'limited to the employment of separate suction'and unloader valves but that a single structure may be utilized to perform the functions of both valves, although. the construction as herein shown is now preferred.

I claim: 1. In combination with an air compressor, fluid pressure actuated mechanism, a valve controlled thereby and cooperating with the compressor and arranged when operated to cause the compressor to work without compression, valve mechanism for admitting and releasing compressed air to and from said fluid pressure actuated mechanism, and comprising independent admission and release valves, and a governor proper controlled by the speed of the compressor and u sor and arranged to operate said valves respectively.

2. I11 combination with an air compressor, fluid pressure actuated mechanism, a valve controlled thereby and cooperating with the compressor and arranged when operated'to cause the compressor to work without compression, valve mechanism for admitting and releasing compressed air to and .i'rom said fluid pressure actuated mechanism and comprising independent admission and release valves, and a governor proper controlled by the speed of the compressor and having two plungers movable in unison in accordance with the speed of the compressor and arranged to operate said valves respectively, said plungers being independently adjustable toward or away, from each other.

3. In combination with an air compressor, fluid pressure actuated mechanism, a valve controlled thereby and cooperating with the compressor and arranged when operated to cause the compressor to work withoutcompression, valve mechanism for admitting and releasing compressed air to and from said fluid pressure actuated mechanism and comprising independent admission and release valves, and a governor proper controlled by the speed of the compressor and having two plungers, movable heads or supports therefor, and a yoke connecting said heads whereby the plungers move in unison.

4. In combination with an air compressor, fluid pressure actuated mechanism, a valve controlled thereby and cooperating with the compressor and arranged when operated to cause the compressor to work without compression, valve mechanism for admitting and releasing compressed air to and from said fluid pressure actuated mechanism, and comprising a casing having communication with said fluid pressure actuated mechanism, with the atmosphere and with a source of compressed air, valves in the casing for governing respectively said communication with the atmosphere and the communication between said fluid pressure actuated mechanism and the source of compressed air, and a governor having plungers for operating said valves in accordance with the speed of the compressor.

5. In combination with an air compressor, fluid pressure actuated mechanism, a valve controlled thereby and cooperating with the compressor and arranged when operated to cause the compressor to work without compression, valve mechanism for admitting and releasing compressed air to and from said fluid pressure actuated mechanism, and comprising a casing having communication with said fluid pressure actuated mechanism, with the atmosphere and with a source of compressed air, two ball valves in the casing for governing said communications, and a governor having plungers for operating the valves in accordance with the speed of the compressors.

6. In combination with an air compressor, fluid pressure actuated mechanism, a valve controlled thereby and cooperating with the compressor and arranged when operated to cause the compressor to work without compression, valve mechanism for admitting and releasing compressed air to and from said fluid pressure actuated mechanism, and comprising a casing having communication with said fluid pressure actuated mechanism,with the atmosphere and with a source of compressed air, two ball valves in the easing for governing said communication, springs tending to hold the valves seated, and a governor having plungers for operating the valves in accordance with the speed of the compressor, said plungers being arranged to open one valve and to permit the other to close.

7. In combination with an air compressor, fluid pressure actuated mechanism, a valve controlled thereby and cooperating with the compressor and arranged when operated to cause the compressor to work without compression, valve mechanism for admitting. and releasing compressed air to and from said fluid pressure actuated mechanism, and comprising a casing having communication with said fluid'pressure actuated mechanism, with the atmosphere and with a source of compressed air, valves in the casing for gov-- erning respectively said communication with the atmosphere and the communication between said fluid pressure actuated mechanism and the source of compressed air, and a governor having plungers for operating said valves in accordance with the speed of the compressor, said governor having movable heads or supports for the plungers respectively, and a connection between said heads, and an adjustable spring cooperating with one of the heads.

8. In combination with an air compressor, fluid pressure actuated mechanism, a valve controlled thereby and cooperating with the compressor and arranged when operated to cause the compressor to work without compression, valve mechanism for admitting and releasing compressed air to and from said fluid pressure actuated mechanism, and comprising a casing having communication with said fluid pressure actuated mechanism, with the atmosphere and with a source 0 compressed air, valves in the casing for governing respectively said communication-with the atmosphere and the communication be tween said fluid pressure actuated mechanism and the course of compressed air, and a governor having plungers for operating said valves in accordancewith the speed of the compressor, said governor having movable heads in which the plunger-s respec-I bonnets 3 secured to the opposite ends of the 20 tively are screw-threaded for adjustment purposes. v

9. In combination with an air compressor including its cylinder, a pair of valve bonnets 3 secured to the opposite ends of the cylinder and having chambers communicating with the suction ports of the'cylinder, suction valves for said ports, a by-pass connection 2 between said chambers, valves 2 in the chambers for governing communication between the suction ports and the bypass, cylinders 7, secured to the bonnets, a piston 9 in each cylinder 7, which piston is adapted to operate its valve 2, and a fluid pressure supply pipe 11 in common with both cylinders 10. In combination with an air compressor including its cylinder, a pair of valve cylinder and having chambers communicating with suction ports vofthe cylinder, suc tion valves for said ports, a by-pass connection 2 between said chambers, valves 2 in the chambers for governing communication between the suction ports and the by-pass, springs 6 for holding the valves 2 normally seated, cylinders 7 secured to the bonnets, a piston 9 in each cylinder, each of said valves 2 having a stem 5 adapted to be contacted and operated by its piston, and a,

fluid pressure supply pipe'll in common with both cylinders 7.

' EDWIN M. MAGKIE.

Witnesses:

S. E. HIBBEN, LOUIS B. ERWIN. 

